1. Field of the Invention
The present invention relates to a device for limiting the power of transmission of radiowaves.
2. Description of the Prior Art
The invention is primarily applicable to devices for preventing any power overshoot within the amplifying chains of radiowave transmitters, these chains being in turn equipped with gain-regulating systems as well as systems for regulating the output power of the retransmission units.
In order to limit the output power of radiowave transmitters, it is a known practice to use power-limiting stages which usually precede the power-amplifying chain. These power-limiting stages are controlled by a detector which has the intended function of detecting any overshoot, or transition beyond the level of the signal with respect to a predetermined threshold, said detector being located either downstream or upstream with respect to the amplifying chain. Although these devices meet advanced design standards, there is not a single instance in which a device of this type proves fully satisfactory and power overshoots always take place. These power overshoots are usually of short duration and appear, for example, at the time of startup of the amplifying chains, at the time of accidental short-time interruptions in the supply of the transmitters or else in the event of accidental disconnections of transmission antennas or of their amplifying chains. It is readily apparent that, no matter how short they may be, these power overshoots usually produce adverse effects on the operation of the amplifying chains and are liable to result in damaging of certain semiconductor components or electron tubes which constitute the amplifying chains.